


Baby, It's Cold Outside

by LazyRainDancer



Category: Undertale (Video Game)
Genre: Babybones (Undertale), Frisk's Pronouns are They/Them, Gen, I couldn't stop myself, Skeletons turn into babybones, Tooth-Rotting Fluff, just temporarily, yes I made the title a pun, yes it's that popular lab accident cliche
Language: English
Status: Completed
Published: 2018-06-29
Updated: 2018-06-29
Packaged: 2019-05-30 03:38:32
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,323
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15088184
Author URL: https://archiveofourown.org/users/LazyRainDancer/pseuds/LazyRainDancer
Summary: The first Saturday of every month Frisk always went to Alphys and Undyne’s house to watch anime. The three would spend all day together. It was a tradition.So, when Frisk arrived at the household, they were not expecting to see Sans and Papyrus there. Even more surprising was the fact that the two skeletons were now children.Frisk spends the day with their now kid-sized skeleton friends.





	Baby, It's Cold Outside

**Author's Note:**

> This is the fic I wrote for the Summer Secret Santa event on Tumblr. I wasn't originally gonna post it here since this was my first time writing a non Reader insert fic for Undertale and I was nervous about it. However, a sweet anon was having trouble reading it on Tumblr, so I posted it here for them. I hope y'all enjoy it! ^^
> 
> This fic was beta-read by the wonderful disasterbisexual. Thank you so much! <3

After falling Underground and discovering that monsters were real, Frisk thought that nothing could surprise them anymore, especially once they became the ambassador for the monster race after breaking the barrier. Nothing could be crazier than that adventure.

Of course, life had a way of proving them wrong. 

The first Saturday of every month Frisk always went to Alphys and Undyne’s house to watch anime. The three would spend all day together. It was a tradition. 

So, when Frisk arrived at the household, they were not expecting to see Sans and Papyrus there. Even more surprising was the fact that the two skeletons were now children.

Frisk tried to decipher what happened, but Alphys's nervous stutter only increased her panic, causing the explanation to come out in a jumbled mess of words they couldn't string together. Apparently, there was an accident in Alphys’ lab while the skeleton brothers were visiting that somehow turned the brothers into kids, and the anxious reptile has no idea how to fix them.

For reasons unknown to the monsters’ ambassador, Undyne and Alphys thought that leaving Frisk, an older child, but still a child nonetheless, in charge of looking after the baby bones, was a good idea. Once they arrived, the two adults headed straight for the lab to figure out how to turn Sans and Papyrus back to normal.

Apparently, Undyne wanted to keep an eye on Alphys to make sure she didn’t have a panic attack when left alone. Considering how much the anxious reptile had been sweating and trembling, Undyne’s worries were definitely warranted.

So now, Frisk had to figure out how exactly to handle this situation. Thankfully, Sans and Papyrus didn’t appear wary of their much taller friends, possibly because the other monsters welcomed the human child so warmly and were obviously friends with them. 

Upon closer inspection, Frisk realized that the boys’ clothes looked very familiar. Apparently, whatever the skeletons were wearing beforehand didn’t shrink along with them, so the adults decided to lend the baby bones some of the clothes Frisk had left over at their house. Sans and Papyrus were just a few inches shorter than the human now, and their big eyes and somehow chubby-looking cheekbones made Frisk’s heart melt. 

Papyrus beamed as he stared at Frisk with wonder-filled eyes. “WOWIE! A HUMAN! I’VE NEVER SEEN A HUMAN BEFORE! HAVE YOU, SANS?”

His brother shook his head as he gave the human child a once over. “nope. this is a first for me too, pap. guess those ladies weren’t _kid_ -ding around, huh?”

Frisk giggled while Papyrus groaned in displeasure. “THAT WAS AWFUL, SANS!”

Sans grinned at his brother. “really? judging from their expression, i’d say i really _tickled their funny bone_.”

“NOOOOOOOO!”

Little Papyrus’ melodramatic reaction only made Frisk’s laughter increase, and it was quickly joined by Sans’ amused chuckling. This went on for several minutes as the older brother continued to reel out more puns, much to the younger skeleton’s dismay.

After they all calmed down, Frisk decided to try and find a suitable distraction for the baby bones. “It probably wouldn’t be a good idea to go too far, but we can play outside in the snow if you want. Unless you want to watch some of Alphys’ anime?”

While Sans just shrugged at the question, his brother appeared to be considering his options. After a few seconds, Papyrus puffed out his chest eagerly as he announced his decision. “I THINK PLAYING OUTSIDE IS A GREAT IDEA, HUMAN! I CAN SHOW YOU MY SNOWBALL MAKING SKILLS AND SHOW YOU HOW TO MAKE A SNOW SKELETON!”

Of course, adult Papyrus had already shown them this, but Frisk decided to remain quiet, since they didn’t want to disappoint him. Dealing with a sad adult Papyrus is one thing, but there was no way Frisk would ever purposely upset kid Pap. 

With that decided, the three headed for the door. Frisk made sure to find some winter wear for the boys before letting them set a foot outside in the cold. Even though they don’t have skin, the skeletons could still get cold if exposed to the snow long enough. 

Once both young skeletons were equipped with mittens and thick wool scarves, they all went outside, Papyrus in the lead. He proceeded to explain to Frisk the do’s and don’ts of snowball crafting, and they nodded every so often to show they were paying attention.

Right as he finished his explanation, a snowball hit Frisk in the back of the head, making them squeal as the snow touched their skin. When they turned to look for the culprit, they saw Sans wearing his trademark, mischievous grin. 

Before Frisk could retaliate, Papyrus threw a freshly made snowball at the attacker, hitting him square in the face. Sans hadn’t been expecting an attack from his brother, judging from his look of surprise.

“NYEH HEH HEH! DON’T WORRY, HUMAN! I KNOW ALL MY BROTHER’S TRICKS, SO WITH MY HELP, OUR VICTORY IS ASSURED!”

After wiping away the snow, Sans pretended to look offended. “aw, bro, you’re not gonna take my side? say it ain’t _snow_.”

Papyrus’s response was to throw another snowball at the older skeleton who easily evaded the attack.With a grin, Frisk balled up some snow and started hurling it at Sans who used his magic to return fire. 

Once his brother started using magic, Papyrus felt it necessary to reciprocate. As they pelted each other with snow, Frisk decided making a wall to hide behind would be a good idea.

Just as the human finished their project, they got bombarded from snow from above. Frisk emerged from the snow pile to see Sans laughing. Apparently, while they had been distracted, he had used his magic to drop snow on them.

“I’LL AVENGE YOU, HUMAN!”

With a mighty battle cry, Papyrus flung several snowballs at his brother using his magic. Because he was laughing so hard, Sans had been unable to dodge in time, earning him a face full of snow.

Frisk and Papyrus burst into hysterics when they saw that a snowball had gotten stuck in one of the older skeleton’s eye sockets. “NYEH HEH HEH! THAT’LL _SNOW_ YOU, BROTHER!”

After Sans recovered and finally managed to dislodge the clump of snow, the other children took shelter behind the wall Frisk created and started pelting snowballs at the older skeleton, who crouched behind a nearby tree. 

The battle went on for some time before Sans finally surrendered much to the others kids’ joy. They decided to celebrate by making a snow skeleton to look like Papyrus after he was declared the snowball fight’s MVP by Sans and Frisk.

Right after they finished making a very intricate snow Papyrus, both skeletons got engulfed in a cloud of blue smoke. Once it cleared, Frisk was surprised to see that their friends had returned to normal.

At that moment, Alphys darted out the front door. “G-Good news! It’s only temporary! So-”

The reptile froze as she laid eyes on the skeletons and immediately moved to cover her face with a scaly hand. “O-Oh dear.”

Undyne, who had followed Alphys outside, started rolling on the ground, letting out a sharp guffaw as she pounded the snow to a pulp with her fist. 

Frisk’s giggles soon joined Undyne’s laughter as they took in the sight of the adult skeletons wearing the human’s extremely small clothes, which miraculously didn’t tear when the skeleton monsters returned to their normal size. 

Papyrus raised his arms in a feeble attempt to cover his exposed rib cage while Sans just grinned casually, seemingly unconcerned about his current predicament. 

“welp. can’t say i know what’s going on, but maybe the kid can tell us the _bare bones_ of the situation so we won’t be _left in the cold_.”

“SANS!”

Yeah, this was just another day in the life of the young ambassador, and Frisk wouldn’t have it any other way.

**Author's Note:**

> Two of the prompts I was given were "anything with the babybones AU" and "Frisk playing in the snow with Sans and/or Papyrus". I decided to combine the two, and this was the result haha
> 
> I haven't written something in third person in a while so I was nervous about this. I hope y'all enjoyed it! ^-^


End file.
